/**
 * Created with IntelliJ IDEA.
 * Description:给你单链表的头节点 head ，请你反转链表，并返回反转后的链表
 * User: wangxin
 * Date: 2025-04-16
 * Time: 15:08
 */
 class ListNode {
      int val;
      ListNode next;
      ListNode() {}
      ListNode(int val) { this.val = val; }
      ListNode(int val, ListNode next) { this.val = val; this.next = next; }
  }
public class Test {
    public ListNode reverseList(ListNode head) {
        if(head == null||head.next == null){
            return head;
        }
        ListNode newHead = reverseList(head.next);
        head.next.next = head;
        head.next = null;
        return newHead;
    }
}
